A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5905-01-084-7264
NSN 7035-00-445-9657
NSN 2925-01-488-2966
NSN 5999-01-512-9178
NSN 6135-01-322-4655
NSN 5965-01-252-8701
NSN 6150-00-599-0721
NSN 6645-00-270-6817
NSN 6610-01-281-6764
NSN 5960-00-504-1066
NSN 6110-00-533-4334
NSN 5990-01-109-5295